There are numerous bicycle suspension systems in use today to improve performance. Many of these systems tune two important parameters that relate to unwanted suspension motion when the system is responding to pedal inputs. Other systems attempt to optimize the braking response of the suspension system. The present invention tunes both of the pedal performance parameters together to behave in a linear relationship so that their combined effect is highly predictable to the rider. Additionally, a third parameter that is related to improved braking performance is also tuned in the present invention. This parameter is the braking anti-squat percentage. This parameter is also tuned to behave in a linear relationship so that the overall performance of the bicycle is highly predictable under both pedaling and braking.
The first parameter is the rate of change of the distance from the bottom bracket pedal axis to the rear wheel axle, commonly known as dCSL. It is known that it is desirable to have a certain dCSL value at the point in the suspension's compression known as the sag point where the system is in static equilibrium under the rider's weight. However, it is undesirable to have high values for the dCSL at points farther in the suspension's compression as this creates a pull on the pedals when a larger bump is encountered as when riding over very rough terrain. The known systems that employ a reduction in dCSL as the system is further compressed generally display a curved relationship between dCSL and the vertical wheel travel resulting in unpredictable response to the rider when encountering bumps of various sizes. The present invention employs a reduction in dCSL with respect to increasing vertical wheel travel while displaying a linear relationship. This results in highly predictable response. The second parameter is the acceleration anti-squat effect created by the kinematics of the suspension system. This effect is tuned so that a weight transfer rearward as a result of forward acceleration does not result in varying amounts of suspension compression throughout the compression of the system. A value of 100% anti-squat results in no suspension compression as a result of weight transfer. The known systems that employ anti-squat to tune the compression of the suspension generally display a curved relationship of percent anti-squat vs. vertical wheel travel. The present invention employs a reduction in percentage anti-squat with respect to increasing vertical wheel travel while displaying a linear relationship. Additionally, the point where 100% anti-squat is achieved is at the linear sag point. This results in an optimally tuned system that is very predictable throughout the range of suspension motion.